Here's the basics. FFmpeg was developed for Linux, but there are builds available for Windows. It's in a constant state of development. It's a command-line controlled program (Do you still DOS?) Documentation is poor. Some video transcoding software utilizes FFmpeg. There are also several "FFmpeg GUIs", which come with a particular version of FFmpeg, which is usually outdated. Often the GUI can not interface with a newer version of FFmpeg. FFmpeg has it's own internal encoders which are quite fast. Some builds of FFmpeg also include open-sauce, free, encoders like LameMp3 and XviD, which allow you to use whatever version of the out-sourced encoder was built into the FFmpeg executable/binary/windows program. <br/> <br/>FFmpeg includes a myriad of command-line options/switches to control encoding. These are very poorly documented (i.e. range and type of permissible values are not given). If you enter '-h' at a command prompt, you'll get a list of available options/switches which may or may not be up-to-date or applicable to that particular version. Interestingly the documentation at the FFmpeg website doesn't list half as many options as you get from the HELP function. <br/> <br/>If you can ever understand all the various options, you may be able to create high-quality encodes. ;-) <br/>If you're a DOS command-line freak, this is your day.